Abstract [en]

Purpose: Emotional distress, in terms of anxiety and depression, is common among patients who survive a sudden cardiac arrest (SCA). The Hospital Anxiety and Depression scale (HAD) is one of the most used instruments to assess emotional distress in SCA survivors. However, it has not to our knowledge been psychometrically tested in this group of patients. The aim was therefore to evaluate the measurement properties of the HAD in SCA survivors.

Materials and methods: Data from the Swedish Register of Cardiopulmonary Resuscitation was used. In the register, data is collected 3–6 months after resuscitation by using a questionnaire including HAD. Data quality was evaluated according to the distribution of item and scale score and missing data patterns. A principal component factor analysis was conducted to explore the factor structure. Internal consistency was evaluated with Cronbach's alpha.

Results: The sample consisted of 498 in-hospital survivors with a mean age of 69.3 ± 12.6 years. All items demonstrated problems with floor effects. The scale scores for both anxiety and depression deviated significantly from a normal distribution (p < 0.001). The factor analysis reproduced the hypothesized two-factor structure, which explained 59% of the total variance. The factor loadings varied between 0.547 and 0.778 for anxiety and between 0.651 and 0.780 for depression. Cronbach's alpha was 0.874 and 0.875 for anxiety and depression respectively.

Conclusions: The HAD demonstrated good measurement properties among SCA survivors. Despite problems with floor effects, the two HAD scales, anxiety and depression, seem to be uni-dimensional measures with good internal consistency. Therefore, the HAD can be recommended to assess emotional distress among SCA survivors.